This grand piano's marquetried satinwood case, executed by George H. Blake, is unsurpassed in elegance and iconographic complexity. The piano was commissioned from the London branch of the distinguished French firm of Erard by Thomas Lord Foley, baron of Kidder, minister for Witley Court, for his residence in Herefordshire/Worcestershire. Erard's eighty-note, double-escapement action piano was the most advanced of its time. The basis for modern grand actions, it accommodated the virtuosic pianism of Chopin and Liszt. The hammers are covered with felt, first used in place of leather coverings in 1826. Strings of the top twenty-six notes pass through a perforated brass bar that secures them against the hammers' strong blows. Longitudinal steel bars reinforce the open-bottomed case. The painted and gilded stand is a separate construction in the Louis XV style.Sebastian Erard (1752–1831), who made his first piano in 1777, manufactured harps and pianos, as well as published sheet music. Founding his firm in Paris in 1768, he served many French aristocrats: the duchesse de Villeroy provided him with a workshop, and he designed a special transposing piano for Marie Antoinette. The French Revolution seriously impaired sales (many of Erard's early instruments were confiscated from the aristocracy and burned), so he opened a second manufacturing and sales facility in London.Erard's first pianos featured an English-style action (key mechanism), but by 1822 his brother and business partner Pierre had patented an improved mechanism featuring a double escapement, to permit players to repeat notes with greater speed and control. This action, with a few refinements, is used in today's grand pianos.The cast iron frame had been patented in America in 1825, but European piano makers hesitated to adopt this feature (Conrad Graf continued to make wood cases until about 1840). In 1825, the Erard firm patented a frame constructed of iron bars and plates. While not as rigid and effective as the cast iron frame, the bolted-on iron bars, mounted both above and below the soundboard, greatly improved tuning stability. Many prominent musicians, including Haydn and Beethoven, used Erard pianos. Liszt made his sensational Paris and London debuts on Erard pianos fitted with the newly invented double-repetition action.